up vote 7 down vote accepted When you are starting your kafka broker you can define set of properties in conf/server.properties file. This file is just key value property file. One of the property is auto.create.topics.enable if it set tot true(by default) kafka will create topic automatically when you send message to non existing topic. All config options you can find here Imho Simple rule for creating topics is the following: number of replicas must be not less than number of nodes that you have. Number of topics must be the multiplier of number of node in your cluster for example: You have 9 node cluster your topic must have 9 partitions and 9 replicas or 18 partitions and 9 replicas or 36 partitions and 9 replicas and so on

"isr" is the set of "in-sync" replicas.

no data loss will occur as long as producers and consumers handle this possibility and retry appropriately.

By electing a new leader as soon as possible messages may be dropped but we will minimized downtime as any new machine can be leader.

The high watermark is the offset of the last message that was successfully copied to all of the log’s replicas.